Apparatus for Non-invasive Determination of Sound Velocity in a Liquid and Determining a Parameter of the Liquid from the Sound Velocity

• US 20130304404A1
• Filed: 11/15/2011
• Published: 11/14/2013
• Est. Priority Date: 11/15/2011
• Status: Active Grant

• Current Assignee: Naim Dam
• Original Assignee: Hema-Q Incorporated
• Inventors: Dam, Naim
• Granted Patent: US 8,714,017 B2
• Time in Patent Office: Days
• US Class Current: 702/54
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: A61B 8/0858 involving measuring tissue layers, e.g. skin, interfaces
• CPC Class Codes: A61B 8/4209 by using holders, e.g. positioning frames

Abstract

Apparatus for determining the sound velocity of a liquid in a specimen having two walls between which the liquid is contained with one of the walls being deformable has a sensor including a transducer for transmitting ultrasonic energy signals between the specimen walls and apparatus for deforming the specimen wall by a known distance from a first to a second position relatively spaced from the transducer and an electronic circuit including a microprocessor for measuring first and second transit times of the signals through the liquid between the specimen walls for each of the specimen deformable wall first and second positions, and for calculating the sound velocity of the liquid based upon the known distance and the two measured transit times. Where blood is the liquid values of parameters such as glucose and hematocrit are obtained based on algorithms pre-programmed in the microprocessor.

Claims

1. Apparatus for determining the sound velocity of blood in a specimen as a measure of the glucose value of the blood, said specimen having two walls between which the blood is contained and with one of the specimen walls being deformable, comprising:

a sensor including a transducer for transmitting ultrasonic energy signals between the two walls of the specimen;

deforming apparatus for deforming said one wall of the specimen by a known distance from a first position spaced from said transducer to a second position closer to said transducer; and

an electronic circuit including a microprocessor for measuring a respective first and second transit time of said ultrasonic energy signals through the blood between the two walls of the specimen walls for each of said first and second positions of the deformable specimen wall, and for calculating the sound velocity of the blood based upon said known distance and the said measured first and second transit times, and determining the glucose value of the blood.

2. The apparatus as claimed in claim 1 wherein said microprocessor calculates the sound velocity in accordance with the formula

3. The apparatus as claimed in claim 1 wherein said deforming apparatus comprises:

a reflector engaging the exterior of the specimen one deformable wall, said reflector having a first segment with a flat strip and a second segment with a projection extending from said flat strip by said known distance, and wherein said ultrasonic energy signal is transmitted through both specimen walls and reflected from both said reflector segments back to said transducer through the liquid and the two walls of the specimen.

4. The apparatus as claimed in claim 3 wherein said electronic circuit further comprises:

a gating circuit for selecting the signal reflected back to said transducer for use in calculating each of said first and second transit times.

5. The apparatus as claimed in claim 1 wherein said deforming apparatus comprises:

a position control module having a part that engages the exterior of the specimen deformable wall and is operable to move the part to deform the wall from said first position by said known distance to said second position.

6. The apparatus as claimed in claim 5 wherein said part comprises:

a reflector that reflects said signal back to said transducer and wherein said electronic circuit operates to measure said first and second transit times sequentially with the specimen deformable wall at said corresponding first and second positions.

7. The apparatus as claimed in claim 5 wherein said part comprises:

a second transducer that receives the signal from said transducer transmitting said ultrasonic energy signals upon the specimen deformable wall being at each of said first and second positions, and said electronic circuit operates to measure said first and second transit times sequentially with the specimen deformable wall being at said first and second positions.

20. The apparatus as claimed in claim 1 wherein said microprocessor determines the glucose value of the blood in accordance with an algorithm:

V=1496.5+0.0036g−

7×

10<sup>−

8</sup>g²

in the equation

V=blood sound velocity in m/sec (meter/sec) and

g=the glucose concentration in mg/dl (milligrams/deciliter).

23. The apparatus as claimed in claim 1 wherein the specimen is a flexible tube carrying a patient'"'"'s blood.

24. The apparatus as claimed in claim 1

wherein said apparatus further comprises a housing having a slot therein formed by first and second slot walls into which the specimen is placed,

wherein said transducer transmitting said ultrasonic energy signals is mounted in one of said walls of said slot to interact with one wall of the specimen;

wherein said deforming apparatus includes a reflector mounted in the other of said slot walls to reflect said signal back to said transducer, said reflector having a first segment with a flat strip and a second segment with a projection extending from said flat strip by said known distance, said ultrasonic energy signal being transmitted through both specimen walls and reflected from both said reflector segments back to said transducer through the two specimen walls;

wherein said microprocessor determines at least one of the glucose and hematocrit values of the blood; and

wherein said specimen is a portion of a patient'"'"'s body that fits in the slot, the blood that is measured is the blood of the patient in that portion of the patient'"'"'s body, and the measurement is made in real time without contacting the blood.

8. Apparatus for non-invasive determination of the sound velocity of blood in a specimen as a measure of at least one of the glucose and hematocrit value of the blood, said specimen having two walls between which the blood is contained and with one of the specimen walls being deformable, comprising:

a housing having a slot therein formed by first and second walls into which the specimen is placed,

a sensor including a transducer transmitting said ultrasonic energy signals is mounted in one of said walls of said slot to interact with one wall of the specimen;

deforming apparatus for deforming said one wall of the specimen by a known distance from a first position spaced from said transducer to a second position closer to said transducer, said deforming apparatus including a reflector mounted in the other of said slot walls to reflect said signal back to said transducer, said reflector having a first segment with a flat strip and a second segment with a projection extending from said flat strip by said known distance, said ultrasonic energy signal being transmitted through both specimen walls and reflected from both said reflector segments back to said transducer through the two specimen walls and

an electronic circuit including a microprocessor measuring a respective first and second transit time of said ultrasonic energy signals through the blood between the specimen two walls for each of said first and second positions of the deformable specimen wall, calculating the sound velocity of the blood based upon said known distance and the said measured first and second transit times, and determining at least one of the glucose and hematocrit values of the blood;

wherein said specimen is a portion of a patient'"'"'s body that fits in the slot, the blood that is measured is the blood of the patient in that portion of the patient'"'"'s body, and the measurement is made without contacting the blood.

9. The apparatus as claimed in claim 8 further comprising:

a reflector mounted in the other of said slot walls to reflect said signal back to said transducer.

10. The apparatus as claimed in claim 9 wherein said reflector comprises:

a first segment with a flat strip and a second segment with a projection extending from said flat strip by said known distance, and

wherein said ultrasonic energy signal is transmitted through both specimen walls and reflected from both said reflector segments back to said transducer through the two specimen walls.

11. The apparatus as claimed in claim 10 wherein said electronic circuit further comprises:

a gating circuit for selecting the signal reflected back to said transducer for use in calculating each of said first and second transit times.

12. The apparatus as claimed in claim 8 wherein said deforming apparatus comprises:

a position control module having a part that engages the exterior of the specimen deformable wall and is operable to move the part to deform the wall from said first position by said known distance to said second position.

13. The apparatus as claimed in claim 12 wherein said part comprises:

a reflector that reflects said signal back to said transducer and wherein said electronic circuit operates to measure said first and second transit times sequentially with the specimen deformable wall at said corresponding first and second positions.

14. The apparatus as claimed in claim 12 wherein said part comprises:

a second transducer that receives the signal from said transducer transmitting said ultrasonic energy signals upon the specimen deformable wall being at each of said first and second positions, and said electronic circuit operates to measure said first and second transit times sequentially with the specimen deformable wall being at said first and second positions.

15. The apparatus as claimed in claim 8 wherein said housing comprises:

first and second sections with each of said housing sections defining a respective wall of said slot, and

a resilient means for connecting said first and second housing sections for permitting said first and second housing sections to a move relative to each other, said sections and resilient means forming an earlobe clip, said specimen being the ear lobe of a patient, and the blood measured being the blood in the patient'"'"'s earlobe.

16. The apparatus as claimed in claim 15 wherein said deforming apparatus comprises:

a reflector engaging the exterior of the specimen one deformable wall, said reflector having a first segment with a flat strip and a second segment with a projection extending from said flat strip by said known distance, and wherein said ultrasonic energy signal is transmitted through both specimen walls and reflected from both said reflector segments back to said transducer through the liquid and the two walls of the specimen.

17. The apparatus as claimed in claim 15 wherein said deforming apparatus comprises:

a position control module having a part that engages the exterior of the specimen deformable wall and is operable to move the part to deform the wall from said first position by said known distance to said second position.

18. The apparatus as claimed in claim 17 wherein said part comprises:

a reflector that reflects said signal back to said transducer and wherein said electronic circuit operates to measure said first and second transit times sequentially with the specimen deformable wall at said corresponding first and second positions.

19. The apparatus as claimed in claim 17 wherein said part comprises:

a second transducer that receives the signal from said transducer transmitting said ultrasonic energy signals upon the specimen deformable wall being at each of said first and second positions, and said electronic circuit operates to measure said first and second transit times sequentially with the specimen deformable wall being at said first and second positions.

21. The apparatus as claimed in claim 18 wherein said microprocessor determines the hematocrit value of the blood in accordance with an algorithm:

V=1499.46+0.8871HCT 

 

(6)

where

HCT=hematocrit level in percentage

V=blood sound velocity in m/sec

22. The apparatus as claimed in claim 8 wherein said microprocessor determines the glucose value of the blood in accordance with an algorithm:

V=1496.5+0.0036g−

7×

10<sup>−

8</sup>g²

in the equation

V=blood sound velocity in m/sec (meter/sec) and

g=the glucose concentration in mg/dl (milligrams/deciliter).